In vehicular electronic devices, data is generally transmitted by using a controller area network (CAN) protocol. The CAN has a transmission speed of a maximum of 1 Mbps. In particular, since the transmission speed of 1 Mbps is guaranteed only within 40 m, the transmission speed of 1 Mbps is limited in use, but the size of the data such as a value of a temperature or an RPM is small, but the transmission speed is optimized to a role to share primary state information.
Accordingly, an additional technique is required to transmit large data such as additional information for debugging, and the like to the outside at a short period in addition to state information generated while performing the existing operation.
As a technique for overcoming a communication limit of a CAN environment and transmitting the large data, methods including data compression, data fragmentation, Ethernet frame conversion, and the like are proposed.
When a method for compressing data by using a compression algorithm, such as a delta compression technique, and the like cannot satisfy a required compression rate, loss or delay can occur as large as data which cannot be compressed during communication and when an additional operation is required due to characteristics of an embedded system having a limited system resource, the additional operation can interfere with the existing operation.
A data fragmentation technique that fragments data into pieces according to a data field size of a CAN data frame has a limit in that in the case of an ECU having a limited storage space such as a buffer in an environment in which the data is continuously generated, previously generated data can be lost and modifying an additional communication driver for modifying and using reserved bits of the CAN data frame is required.
An Ethernet frame conversion method using a conversion device has a limit in that the size of data transmittable per unit time does not increase, and as a result, the data generated at the previous time can be lost and in general, an Ethernet interface is not mounted on the ECU, and as a result, the ECU is limited in use.
Since the methods in the related art are limited in transmitting the large data to the outside by using the CAN protocol in an environment in which using a system resource is limited and separate hardware modification is unavailable, a new technique for transmitting the large data is required.